The present invention relates to a device and to an application of this device allowing measurements and/or servicing to be carried out in a well at the level of the surrounding formations.
The invention is notably applicable when the measurements and/or servicing are to be carried out at the level of geologic formations crossed through by a well. In this case, the measurements performed may comprise recording the bottomhole pressure and temperature, measuring the electrical resistivity, as well as acoustic, nuclear measurements, etc. Perforating guns, completion tools or visual display cameras may also be used.
These measuring and/or servicing techniques are known by specialists and will not be described more in detail hereafter.
The present invention is particularly well suited for carrying out measurements and/or servicing in an oil production well comprising a drain strongly inclined with respect to the vertical or even horizontal.
U.S. Pat. No. 4,685,516 describes a well-known system for carrying out measurements or servicing in a well, comprising a metallic tubing coiled by plastic strain around a drum, with an electric transmission cable being slipped into the tubing. Setting such a cable is problematic because it can only be achieved when the tubing is completely uncoiled. Moreover, the plastic strains induced by coiling around the drum decrease the reliability of the system because of the fatigue resulting therefrom. It is the same for corrosion processes.
In French 2,631,708 describes a device for carrying out measurements and servicing in a well, which improves the technique by solving most of the drawbacks of the device cited above. But the rod disclosed in this document presents the disadvantage of having such a rigidity that the diameter of the drum is too bulky.